Identification Properties
• LUSTER
– The shine in
reflected
light
LUSTER TERM DESCRIPTION
adamantine very brilliant - as in diamond
resinous
looks like resin or hardened
tree sap
vitreous
glassy, but not as shiny as
diamond
metallic looks like metal
silky has a smooth and fibrous sheen
pearly smooth and iridescent
greasy looks like it's coated with oil
earthy looks like dirt
LUSTER
• Glassy
•
• Adamantine
•
• Greasy
CRYSTAL SHAPE
Identification Properties
• STREAK
– Color of its powder
– Does not change
– Metallic: as dark as
sample
– Nonmetallic: white to
colorless
Streak Plate ↑
Identification Properties
• CLEAVAGE
– Tendency to split easily
or break along flat
surfaces
– Mica – 1 direction
• FRACTURE
– Break on uneven
surfaces
– Conchoidal - obsidian
Identification Properties
• HARDNESS
– Resistance to being
scratched
– Mohs’ Scale of
Hardness
Mohs’ Scale of Hardness
• 1 - Talc – fingernail scratches it easily
• 2 - Gypsum – fingernail scratches it
• 3 - Calcite – copper penny just scratches it
• 4 - Fluorite – steel knife scratches it easily
• 5 – Apatite – steel knife scratches it
• 6 – Feldspar – steel knife does not scratch it
easily; it scratches window glass
Mohs’ Scale of Hardness
• 7 – Quartz – hardest common mineral; it
scratches steel and hard glass easily
• 8 – Topaz – harder than any common
mineral
• 9 – Corundum – it scratches topaz
• 10 – Diamond – hardest of all minerals
Hardness:
resistance of
a mineral to
abrasion
scratching
Special Identification Properties
• Magnetism
Magnetite
Special Identification Properties
• Taste
• This will quickly identify the mineral halite (salt). If you
are new to this process you must use this one with caution,
as you never know what the unknown may be.
• Often, you may need to resort to this method (until you
more fully understand other identifying traits) to
differentiate halite from calcite.
• If you do taste the sample (especially in a class
environment) you should realize that it has been handled
by and probably tasted by hundreds of others.
Minerals
Chalcopyrite
Quartz
Talc
Jasper
Topaz
Gypsum
Hematite
Galena
Calcite
Amber
Muscovite
Fluorite
Malachite
Biotite
Apatite
Halite
Magnetite
Feldspar
Rocks and the Rock Cycle
Prof. Dr. Ziad Abu-Hamatteh
Faculty of Engineering Technology
Al-Balqa’ Applied University
Rocks and the Rock Cycle
“The present is the key to the past”
• Geologic processes that happen today happened
in the past
• Earth’s present physical features were formed
by these processes
